Conventionally, a wiper device wiping off excrescences such as rainwater and dust on a wipe surface of a windshield is equipped with a vehicle such as an automobile and ensures the range of view of a driver. The wiper device is provided with: a wiper motor (drive source), a wiper arm (arm) subjected to swinging drive via a link mechanism, and a wiper blade wiping the wipe surface. The wiper blade is set up in a distal-end side of the wiper arm and provided with a blade rubber in sliding contact with the wipe surface, and a rubber holder retaining the blade rubber. When a wiper switch inside the vehicle is operated to subject the wiper motor to rotary drive, the wiper arm is subjected to swinging drive via the link mechanism. As a result, the wiper blade operates reciprocating wiping on the windshield and wipes off the excrescences onto the wipe surface.
A wiper device mounted in a vehicle is provided at a front-end part of the windshield, and the wiper blade is disposed outside the vehicle. Therefore, the wiper blade receives travel winds during travelling of the vehicle. Particularly, if the vehicle travels at high speed, lifting force lifting up the wiper blade from the windshield is generated, and a problem that the wiping performance of the wiper blade is reduced is generated. Therefore, wiper blades with various shapes have been developed to suppress the lifting force acting on the wiper blade, (for example, Japanese Utility Model No. 3107550 and JP Publication No. 2007-176459).
The wiper blade described in Japanese Utility Model No. 3107550 or JP Publication No. 2007-176459 has a fin part provided with an inclined surface along the longitudinal direction of the blade rubber. If travel winds are received from the inclined-surface side (front-surface side) of the fin part, for example, when the vehicle travels at high speed, downforce pressing the blade rubber toward the wipe surface is generated. Uplift of the blade rubber from the windshield is suppressed by the generation of the downforce, and then the wiping performance of the wiper blade is improved.
However, according to the wiper blades described in Japanese Utility Model No. 3107550 and JP Publication No. 2007-176459, in the back-surface side of the wiper blade, the separated distance between the travel wind and the wipe surface is longer compared with that in the front-surface side of the wiper blade to provide the fin part generating downforce. Therefore, when the travel winds flow along the inclined surface of the fin part from the front-surface side of the wiper blade toward the back-surface side, comparatively-large swirls (negative pressures) are generated in the back-surface side of the wiper blade. Particularly, when the swinging direction of the wiper blade to the windshield is switched from an upper reversing position to a lower reversing position, the swirls cause a problem (water draw-in phenomenon) that the rainwater, etc. wiped off until the wiper blade reaches the upper reversing position from the lower reversing position are drawn into the wiping range of the wind shield.